I need to get answers for some questions related to Graph Theory. I

** The Questions: **(inside the attached file)**

[1] 6.1.28

[2] 6.3.3

[3] 6.3.19 (When proving graph is not hamiltonian, you should use proof by contradiction)

[4] 6.5.11 (prove why you can’t find a hamiltonian circle )

[5] 6.5.12 (prove why you can’t find a hamiltonian circle )